Does anyone know about grey water systems for automobile service stations?

Dear friends at water network,

I have an question,

My country Jordan is one of the world's poorest countries in terms of water; water issue is a very important and become scarce and more expensive. Every single person in Jordan suffering due to water scarcity; Thousands of cars service stations and a lot of commercial, private and government institutions need innovation solutions.

Does anyone know about grey water systems that may use for the car washing centers?

Does someone already have developed any system of the same purpose?

 Many thanks,